Dissertation
Dissertation > Industrial Technology > Light industry,handicrafts > Food Industry > Fruits, vegetables,nuts processing industry

Study on Osmotic Dehydration Combined Fluidized Bed Drying of Blueberries

Author DongQuan
Tutor ChenZongDao;Dr.Michèle Marcotte
School Southwest Agricultural University
Course Agricultural Products Processing and Storage
Keywords Low highbush blueberry Osmotic dehydration Fluidized bed Anthocyanins Diffusion rate
CLC TS255
Type PhD thesis
Year 2005
Downloads 775
Quotes 6
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Low highbush blueberry (Vaccinium angustifolium) osmotic dehydration and fluid bed drying key technologies. Blueberry origin in North America, in recent years, many provinces and cities in China have begun to introduction and try to grow blueberries, blueberries are good prospects for development in China. Osmotic dehydration of fruits and vegetables at a certain temperature, the material is placed in a high concentration of solution, the use of cell membranes semi-permeable so that the material moisture transfer to the solution, a technique of removing part of the moisture. Compared with the traditional hot air dehydration due to the phase change of water transfer and low penetration dehydration temperature, thus penetrate dehydrated with low energy consumption, less loss of nutrients, to keep the the products original color, smell and taste good characteristics, the more increasingly widespread concern by the world food industry. In production, the osmotic dehydration can be used as a pre-treatment of fruit and vegetable processing, and fruit and vegetable drying, freezing, canning, etc. Methods used in combination. The study results showed that the the blueberry water content and water activity with osmotic dehydration time prolong reduced, but also with penetration increase in temperature reduces. However, in three different temperature processing, processing with high-fructose corn syrup the blueberry water content and water activity dropped faster than sucrose solution processing. Blueberries in the high-fructose corn syrup (70 ± 1 ° Brix) osmotic dehydration treatment temperature 45 ° C, 55 ° C, 65 ° C for various moisture content under the slope of the line of absolute value with increasing temperature increases, the correlation coefficient R 2 of order 0.9626,0.9696,0.9576. Blueberries in a sucrose solution (70 ± 1 ° Brix) osmotic dehydration treatment temperature 45 ° C, 55 ° C, 65 ° C for various moisture content under the slope of the line of absolute value also increased with increasing temperature, the correlation coefficient R 2 of order 0.9815,0.941,0.9228. Blueberries in the high-fructose corn syrup (70 ± 1 ° Brix) osmotic dehydration treatment temperature 45 ° C, 55 ° C and 65 ° C the absolute value of the slope of the line of water activity with increasing temperature increases, the correlation coefficient R 2 of order 0.9700,0.9827,0.9794. Blueberries in a sucrose solution (70 ± 1 ° Brix) osmotic dehydration treatment temperature 45 ° C, 55 ° C and 65 ° C the absolute value of the slope of the line of water activity also increased with increasing temperature, the correlation coefficient R 2 of order 0.9565,0.9739,0.9732. The research results show that the osmotic dehydration the temperature affect the blueberries dehydration rate and Solids acquisition rate. Osmotic dehydration of high fructose corn syrup (70 ± 1 ° Brix), with the penetration of the temperature rise, blueberries dehydration rate increases. Dehydration rate increases in 3h but later dehydration rate rise slowly, close to the limit. Osmotic dehydration of high fructose corn syrup (70 ± 1 ° Brix), as infiltrate temperature rise, blueberries Solids obtain rate increases. Solids in 3h acquisition rate soared, but late Solids acquisition rate to rise slowly, close to the limit. Solids acquisition rate at 65 ° C the case with the other two processing reached a very significant difference (P LT; 0.01), while the infiltration temperature to 45 ° C and 55 ℃ the two processing late (5 ~ 8h) solid The rate of sexual material to obtain the difference was not significant. Calculated based on the effective rate of moisture diffusion model calculated blueberry effective moisture diffusivity in the osmotic dehydration of high fructose corn syrup, at 45 ° C, 55 ° C, 65 ° C under the effective moisture diffusion rate of 4.0916 × 10 -10 m 2 / s, 5.2097 × 10 -10 m 2 / s, 5.2366 × 10 -10 m 2 / s, correlation coefficient R 2 of order 0.9369,0.9203,0.9742. Calculation model, based on the effective moisture diffusion rate calculated blueberry effective moisture diffusivity sucrose solution osmotic dehydration, at 45 ° C, 55 ° C, 65 ° C under an effective moisture diffusivity

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